Retractible boring head for mining machine



Nov. 15, 1966 J. GONSKI 3, 67

RETRACTIBLE BORING HEAD FOR MINING MACHINE Filed Jan. 29, 1964 2 Sheets-Sheet 1 INVENTOR.

BY Joseph Gonski #W a 5M Nov. 15, 1966 J. GONSKI RETRACTIBLE BORING HEAD FOR MINING MACHINE Filed Jan. 29, 1964 2 Sheets-Sheet 2 R Q m N E w V w m m Arm w mm M 3 M Q mm mk Q Q E o R m 0 mm L, mm o o o o 4 Q I I: 1 1 w \7 I, o o o o O W k H\ 8 Q E Q mm o m .3 km 2 m g Joseph Gonski #WZ ma ATTORNEY Patented Nov. 15, 1966 This invention relates generally to a boring type mining machine and more particularly to a retractible boring head therefor.

An object of the present invention is to provide increased cutting range for the boring head of a mining machine, another object is to provide a movable support for a telescopic cutter member, a still further object is to provide such a support which is effective at various boring diameters.

These and other objects and advantages of the invention will appear more fully from the following description together with the drawings.

In the drawings:

FIGURE 1 is an elevation view, in section, of a boring head for a mining machine;

FIG. 2 is a view similar to FIG. 1, showing the cutter member in retracted position;

FIG. 3 is a view taken along the line 3-3 of FIG. 1 looking in the direction of the arrows;

FIG. 4 is an elevation view, in section, of an alternate embodiment of the invention; and

FIG. 5 is a view similar to FIG. 4 showing the cutter in retracted position.

Referring now to FIGURE 1 the numeral 10 refers generally to a boring head for a mining machine. As shown here, the head 10 is formed integrally with a hollow shaft 11 but may be formed as a separate part when desirable. Shaft 11 is journaled for rotation in bearings 12 and 13. Bearing 12 is seated in a gear box 14 and is retained by cap 16 and cap screws 17. A grease seal 18 in cap 16 seals bearing 12 against the intrusion of dirt and the like. Gear box 14 is mounted on a mobile mining machine frame not shown in the drawings. Bearing '13 is seated in the rear wall of gear box 14 and is retained by cap 19 and cap screws 21. A nut 22 secures the inner race of bearing 13 on shaft 11. A drive gear 23 is in splined engagement with shaft 11 and is retained longitudinally of the shaft by a snap ring 24. Drive gear 23 is representative of the drive means for shaft 11 including other gears and a drive motor not shown in the drawings.

Shaft 11 is hollow to provide room for a double acting piston and cylinder combination 26. An axial projection 27 extends rearwardly from cylinder 26 and has a shoulder 28 which engages insert 29 in cap 19. Shoulder 28 and nut 31 secure cylinder 26 against axial movement. A key 32 secures the cylinder against rotation. Projection 27 is ported and internally channeled to provide conduits for pressure fluid acting on the faces of the piston. A bearing 33 supports the folward end of nonrotating cylinder 26 in rotatable shaft 11. A nut 34 secures the inner races of bearing 33 to cylinder 26. A piston rod 36 extends forwardly into threaded engagement with a disc 37 which is secured between a pair of thrust bearings 38 and 39. Thrust bearings 38 and 39 are secured in slide 41 by cap 42 and cap screws 43. Slide 41 has a pair of recesses 44 bridged by pivot pins 46.. Links 47 are pivoted on pins 46 and extend radially outwardly inside hollow arms 48.

A pilot cutter 49 is mounted on the forward face of boring head 10 and has a recess 51 which provides support for slide 41. An adjustable cutter 52 is also mounted on the forward face of boring head 10. Inside surface 53 in hollow arm 48 has a slotted guideway 54 terminating in end shoulders 56 and 57. Shoulder 57 provides an inwardly facing stop surface. Sleeve 58 is mounted Within arm 48 for sliding movement along inside surface 53. A tongue 59 is fastened to the radially inward end of sleeve 58 by screw 61 to project into slotted guideway 54. Tongue 59 has an outwardly facing stop surface 62 adapted to engage the inwardly facing stop surface of slot 54 when sleeve 58 is extended outwardly to the predetermined outward limit. A grease seal 63 and retainer 64 seal the interface between arm 48 and sleeve 58.

Sleeve 58 has an inside surface 66 in which a second slotted guideway 67 is formed. A retractible cutter member 68 is connected to link 47 by a pin 69 and is fitted for sliding movement in sleeve 58. A tongue 71 is fastened to the radially inward end of cutter member 68 by'screw 72 and extends into guideway 67. Tongue 71 provides an outwardly facing stop surface which is engageable with an inwardly facing stop surface 73 formed by the terminus of guideway 67. The interface between cutter member 68 and sleeve 58 is sealed by a grease seal 74 which is held in place by retainer 76 and screw 77.

As shown by a comparison of FIGURES 1 and 2, the retractable cutter 68 is drawn radially inwardly when piston and cylinder combination 26 is retracted. Where link 47 is of the length shown in the drawings, cutter member 68 slides within sleeve 58 between retracted and extended positions while sleeve 58 can remain stationary with respect to arm 48. With the design as shown in FIGURES l and 2 it is possible to substitute a shorter link in place of link 47 in order to provide a smaller bore diameter. In such case, sleeve 58 would move inwardly to a new location within arm 48 so that stop surfaces 57 and 62 would no longer be in engagement.

Thus, it is seen that sleeve 58 is telescopically embraced within arm 48 and cutter 68 is telescopically embraced within sleeve 58 in such manner that it is necessary to substiute only a new link in place of link 47 to change the effective cutting diameter of boring head 10.

The embodiment of the invention shown in FIGS. 1 and 2 is of a type intended to operate at a single predetermined cutting diameter for any particular link size. As shown in FIG. 1, the links 47 are moved to an over-centered, toggle configuration when fully extended in order to assure that the arm or arms 68 will not be collapsed by external forces.

Where the external collapsing forces to be encountered are not critical, an arrangement as shown in FIGS. 4 and 5 may be used to provide incremental cutting diameters and a smaller retracted diameter. In FIGS. 4 and 5, the various parts are identified by the reference characters used in FIGS. 1 and 2 where the parts are the same or nearly the same. Different reference characters are used to designate parts which differ substantially from each other.

Referring now to FIG. 4, piston rod 36 is threaded into a disc 37 which is clamped between a pair of thrust bearings 38 and 39. Bearings 38 and 3% are secured in a slide 78 adapted to move forward and back in shaft 11 in response to actuation of piston and cylinder combination 26. Slide 78 has a pair of forwardly projecting fingers 79, 79 which extend into channels 81 in spacer block 82. Chain links 83 are pivotally connected to each other between respective of fingers 79 and cutters 68 to provide a flexible reciprocable link between cutter 68 and piston cylinder combination 26. Channel 81 communicates with a curved channel 84 in guide 86 to constrain chain links 83 to a curved path. The end link is pin connected to a rod 87 which is adjustably connected to cutter 68. Rod 87 has a head 88 which is located relative to arm 68 by washers 89. The location of head 88 can be precisely adjusted by transferring washers from one side of the head to the other.

Comparison of FIGS. 4 and 5 shows that a greater clearance is realized in the retracted position when the chain link mechanism is used. It is further apparent that cutter 68 may be operated at any desired position between full extension and full retraction providing small increments of boring diameter adjustment. The arrangement of FIGURES 4 and 5 requires that the full telescopic retraction potential of both sleeve 58 and cutter 68 be used between fully extended and retracted position of cutter 68.

In the embodiments shown in both FIGS. 1 and 4 the sleeve 58 provides support for the cutter member.

While I have shown and described a preferred embodiment of my invention, it is to be understood that various changes can be made in the design and arrangement of parts Within the spirit of the invention and the scope of the following claims.

I claim:

1. In a mining machine;

' a boring head mounted for rotation about an axis;

power means disposed along said axis;

at least one arm extending radially outwardly from said head;

a first stop means on said arm having a first stop surface facing radially inwardly;

a sleeve mounted for sliding telescopic movement relative to said arm having a radially outwardly facing second stop surface in alignment with said first stop surface and effective to limit the outward radial movement of said sleeve;

a cutter member mounted for sliding telescopic movement with respect to said arm and said sleeve eifective, when extended radially outwardly, to move said sleeve radially outward; and

link means connected between said power means and said cutter member effective to move said cutter member outwardly while concurrently moving said sleeve outwardly to an extent determined by said stop surfaces.

2. In a mining machine;

a boring head mounted for rotation about an axis;

power means disposed along said axis;

at least one arm extending radially outwardly from said head;

a first stop surface on said arm, said surface facing radially inwardly;

a sleeve mounted for sliding telescopic movement relative to said arm;

a radially outwardly facing second stop surface on said sleeve aligned with said first stop surface, said first and second stop surfaces cooperating to limit the radially outward movement of said sleeve;

a third inwardly facing stop surface on said sleeve;

a cutter member mounted for sliding telescopic movement with respect to said sleeve and said arm;

link means connected between said power means and said cutter member effective to move said cutter member outwardly within limits determined by said four stop surfaces;

a fourth outwardly facing stop surface on said cutter member aligned with said third stop surface, said third and fourth stop surfaces being effective to move said sleeve outwardly when said cutter member is moved radially outwardly; and

guide means between the arm and cutter member effective to limit movement of the cutter member relative to the arm in all directions except radially relative to the head.

3. In a mining machine;

a boring head mounted for rotation about an axis;

at least one hollow arm projecting radially outwardly from said head having a first elongated slot extending radially outwardly along the inside surface thereof, said slot terminating in an inwardly facing first stop surface; 1

a hollow sleeve mounted for sliding telescopic movement within said arm, having a second elongated slot extending radially outwardly along the inside surface thereof, said second slot terminating in an inwardly facing second stop surface;

a first projection on said sleeve engageable with said first slot having a third stop surface facing radially outwardly;

a cutter member mounted for sliding telescopic movement within said sleeve; and

a second projection on said cutter member engageable with said second slot having a fourth stop surface facing radially outwardly, whereby said second and fourth stop surfaces are engageable to move said sleeve outwardly to a preselected location determined by said first and third stops responsive to radially outward movement of said cutter member.

4. In a mining machine;

a boring head mounted on a tubular drive shaft for rotation about an axis;

reciprocable power means disposed within said drive shaft;

at least one hollow arm projecting radially outwardly from said head having a parti-cylindrical inside surface defining a cavity open at its outer end and communicating with the interior of said drive shaft at its inner end;

an elongated guideway extending outwardly along the inside surface of said arm terminating in an inwardly facing first stop surface;

a hollow sleeve mounted in said arm for sliding movement inwardly and outwardly with respect to said shaft, said sleeve having a guideway extending outwardly along the inside surface thereof terminating in a second inwardly facing stop surface;

a projection on said sleeve engageable with the guideway of said arm having a third outwardly facing stop surface;

a cutter member slideable inwardly and outwardly within said sleeve; and

a link, pivotally connected to said power means and said cutter member, effective to move said cutter member inwardly or outwardly responsive to retraction or extension of said power means;

a second projection on said cutter member engageable with the guideway in said sleeve having a fourth stop surface facing outwardly;

whereby said second and fourth stop surfaces are engageable to move said sleeve outwardly to a pre selected location defined by said first and third stop surfaces responsive to outward movement of said cutter member.

5. Ina mining machine;

a boring head mounted on a tubular drive shaft for rotation about an axis;

shaft;

a pair of coacting stop surfaces, one on said cutter member and the other on said sleeve, arranged to move said sleeve outwardly in supporting relationship to said cutter member responsive to outward movement of said cutter member.

References Cited by the Examiner UNITED STATES PATENTS 2,801,094 7/ 1957 Ball 29980 2,882,031 4/ 1959 Hlinsky 29980 3,035,822 5/1962 Lundquist et al. 2996l 3,109,635 11/1963 Bergmann 29961 ERNEST R. PURSER, Primary Examiner. 

1. IN A MINING MACHINE; A BORING HEAD MOUNTED FOR ROTATION ABOUT AN AXIS; POWER MEANS DISPOSED ALONG SAID AXIS; AT LEAST ONE ARM EXTENDING RADIALLY OUTWARDLY FROM SAID HEAD; A FIRST STOP MEANS ON SAID ARM HAVING A FIRST STOP SURFACE FACING RADIALLY INWARDLY; A SLEEVE MOUNTED FOR SLIDING TELESCOPIC MOVEMENT RELATIVE TO SAID ARM HAVING A RADIALLY OUTWARDLY FACING SECOND STOP SURFACE IN ALIGNMENT WITH SAID FIRST STOP SURFACE AND EFFECTIVE TO LIMIT THE OUTWARD RADIAL MOVEMENT OF SAID SLEEVE; A CUTTER MEMBER MOUNTED FOR SLIDING TELESCOPIC MOVEMENT WITH RESPECT TO SAID ARM AND SAID SLEEVE EFFECTIVE, WHEN EXTENDED RADIALLY OUTWARDLY, TO MOVE SAID SLEEVE RADIALLY OUTWARD; AND LINK MEANS CONNECTED BETWEEN SAID POWER MEANS AND SAID CUTTER MEMBER EFFECTIVE TO MOVE SAID CUTTER MEMBER OUTWARDLY WHILE CONCURRENTLY MOVING SAID SLEEVE OUTWARDLY TO AN EXTENT DETERMINED BY SAID STOP SURFACES. 